Revelations about Challenger confront the presidential panel

Even the celebrities on the blue-ribbon commission charged with investigating the explosion of space shuttle Challenger were upstaged last week by a steady stream of disclosures. First, the New York Times revealed that NASA internal documents had long ago warned about problems with the crucial O rings, the two giant synthetic-rubber washers that seal each joint between the booster-rocket segments. Next, an article in Aviation Week & Space Technology spelled out in extraordinary detail how the starboard booster had caused Challenger's external liquid-fuel tank to explode. Then, NASA released pictures showing a mysterious puff of black smoke apparently emerging from the...